Aleksandar Mitrovic will serve a three-game ban after admitting a charge of violent conduct.
Mitrovic elbowed Manuel Lanzini in last weekend's 3-0 win over West Ham United.
The striker was charged by the Football Association after the incident was reviewed.
A club statement read: "Aleksandar Mitrovic will serve a three-match suspension with immediate effect after he admitted an FA charge of violent conduct and accepted the standard penalty.
"The Newcastle United forward was involved in an incident with West Ham United’s Manuel Lanzini in the 80th minute of the game on Saturday (August 26, 2017).
"The misconduct was not seen by the match officials at the time but caught on video."